In the prior art breakers of the general type of the present invention have been broadly disclosed in U.S. Pat. Nos. such as 4,167,702 and 4,258,349. These structures characteristically employ a rocker handle which is rotatably supported to a frame by a pin and provides a linkage crank which, in turn, is connected by a linkage to a switch actuating rocker. The linkage is connected to the linkage crank and rocker by rotatable pin connections parallel to the handle supporting pin. Characteristically the rocker which has a parallel pin trapped in a guide slot is engaged by a pivoted latch member also with a pin parallel to the others, which holds the latched end of the rocker in position as the rocker is moved by the handle member through the linkages against the movable contact arm to close the breaker contacts. The handle may be able to open the breaker contacts by rotation back the opposite direction. Upon overload, the contacts are opened as the latch member is moved releasing the latched end of the rocker to reposition so that the contacts will be able to open.
The applicant's assignee Heinemann Electric Company has manufactured thermally actuated breakers using a rocker handle. Such a breaker has had a somewhat different configuration shown in U.S. Pat. Nos. 4,338,586 and 4,436,972.